In a stretch-blow molding machine known from DE 10325229 A, an electric linear drive is provided for positioning the stretching rod in electric stretching. To be able to change the stretching rod, the electric linear drive must be dismounted.
In the stretch-blow molding machine known from WO 2006/108380 A, the stretching rod is positioned by an electric linear motor and additionally by a fluid drive. The stretching rod is retained in a stretching slide. A releasable coupling is provided between the stretching rod and either an extension element or a rotor of the linear motor. Time-consuming reset works are required for changing a stretching rod.
In the stretch-blow molding machine known from DE 102005045942 A, the stretching rod movement is cam-controlled, where positioning can be additionally accomplished electrically. A coupling device is arranged at the stretching slide.
In the stretch-blow molding machine known from EP 1694492 A, the stretching rod is releasably connected with the stretching slide via a bayonet-type coupling. The stretching rod is positioned by cam control of the stretching slide. The stretching slide comprises a hollow housing into which a head portion with two ears mounted to the stretching rod can be inserted linearly and locked by rotary motion about the stretching rod axis. The handling of this is complicated.